Police said that “familial DNA” identified the murderer. According to reports, the method is a controversial technique that law enforcement uses to identify likely relatives of suspects.

Klaas, 32, was attacked Jan. 30, 1976 as she returned to her home in Hermosa Beach.

She was sexually assaulted, strangled with her pantyhose and never regained consciousness. She died a few days later at the hospital.

According to Fox News, Sheriff's investigators, seeking help from the public in 2009, said two witnesses spotted a shaggy-haired, bearded man in a trench coat and blue jeans leaving the house, but the man was never seen again.

Officials said they were able to put together a DNA profile of Klaas' killer but in 2009 said it hadn't matched anyone in the national DNA database.